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What happens if you heat fix a slide too long?
If the smear is overheated during heat fixing, the cell walls will rupture. Concentration and freshness of reagents may affect the quality of the stain. Washing and drying of the smear between steps should be consistent. Excess water left on the slide will dilute reagents, particularly Gram’s iodine.
What would you expect to happen if you failed to heat fix the slide?
What would you expect to happen if you failed to heat fix the slide? The stain adheres the bacteria to the slide. The stain provides necessary contrast between the cells and the background.
What is the purpose of heating the slide during the staining process?
Heat fixing kills the bacteria in the smear, firmly adheres the smear to the slide, and allows the sample to more readily take up stains.
Why do slides have to be heat fixed before staining?
Heat fixation ensures the elimination of contaminating organisms from the smear preparation. Heat fixation adheres the cells to the slide and coagulates the bacterial proteins, effectively killing the bacteria. Heat fixation is necessary to provide contrast between the cells and the background.
What would happen if the slide did not dry completely before you heat fix it?
If you don’t completely air dry your slide, you will end up boiling your microorganisms when heat-fixing. When heat-fixing, if you hold the slide over the flame too long, you will incinerate the cells.
Why do the slides need to be heat fixed during the direct stain but not during the negative stain?
**3) Why are smears heat-fixed prior to being used in a direct stain? so that organisms are killed, adhere better to the slide, and take up dye more easily, used in direct staining.
What do you think would happen if the slides were not heat fixed and then stained?
What could happen if you didn’t heat fix it? When you rinse the stain off, it could wash everything off the slide or if you left the slide for viewing the next day, the enzymes could eat up the cell walls.
Why do the slides have to be heat fixed before staining What do you think would happen if the slides were not heat fixed and then stained?
If you don’t completely air dry your slide, you will end up boiling your microorganisms when heat-fixing. 2. When mixing bacteria with water, if you over mix it can result in inaccurate cell patterns. When heat-fixing, if you hold the slide over the flame too long, you will incinerate the cells.
Why did the slides need to be heat fixed during the direct stain but not during the negative stain?
Why is heat necessary in spore staining?
apply heat to assist stain penetration. The heat will force the stain into the spores and vegetative cells, and both will become green. By rinsing the slide, the vegetative cells will lose their color but the spores will remain green.
How do you flame a slide?
In order to heat fix a bacterial smear, it is necessary to first let the bacterial sample air dry. Then either place the slide in the slide holder of a microincinerator, or pass the dried slide through the flame of a Bunsen burner 3 or 4 times, smear side facing up. Once the slide is heat fixed, it can then be stained.